Mono Cartridge Recommendations

In the "old days", it was widely known that using a mono cartridge on a stereo LP was verboten or at best ill-advised.  Some vintage early stereo LP album covers even have that warning printed on the back, in fine print at the bottom right of the text.  This warning is consistent with the concept that a (vintage) true mono cartridge with very low vertical compliance might potentially damage the groove walls of a stereo LP, which encode musical information in the vertical as well as the horizontal direction. Whereas mono LPs produce no musical signal due to vertical deflection of the cantilever.  In those days, many if not most audiophiles owned mono cartridges as their main standby, so it made sense to make sure that those converting to stereo ought to use caution. Clearthink's sarcasm and bad manners are not at all justified. Not that such nastiness is ever justifiable on this forum.

However, in the modern era we have a plethora of new mono cartridges, only a few of which can be said to be "true mono".  Miyajima mono cartridges are some of a very few such cartridges available.  Most other recent production "mono" cartridges are actually stereo cartridges within which the channels are bridged one way or another to produce a mono output.  Such cartridges are likely to have decent vertical compliance, unless they have been radically revised from their stereo origins, and such mono cartridges are not likely to damage a stereo LP.  Whether or not a Miyajima mono (or any of the few other true mono cartridges) can damage a stereo LP, I do not know.  But Robin Wyatt would know.

peter, the answers to many of your questions will depend on the specific monos you listen to.

I’ve read that no mono cutter heads have been available/in use since around 1990. So all of the newer mono reissues were made with a stereo cutter head. For that reason many find any good quality stereo cartridge switched to mono in the preamp or phono stage is all that is needed.

For the earlier true mono recordings a wider stylus tip may perform best for those produced before the stereo era (’57-’58). Monos produced after that up until the end of production (around 1970?) work best with the 0.7 mil styli.

The question of a true mono cartridge VS strapped has been ask many times but I’ve never seen a definitive list.

Oops - not "Robert" of course I meant Robin Wyatt at Robyatt Audio. Obviously I was thinking of this!
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&...

Miyajima Zero mono carts are about 30% cheaper in Europe (or just about anywhere else.)  This is from authorized dealers, some of whom will ship to the US.  US distributor does offer a return period which is certainly worth something though.

The original Decca cartridge was mono (L + R), and when stereo came in the cartridge was modified to create the "difference" (L - R) stereo signal. The cartridge (now marketed as London) used the same cantilever-less design in both stereo and mono cartridges, the armature holding the stylus having very different lateral and vertical compliances. London offers a true mono cartridge, producing only the L + R signal, but it is a high-output (5mV!) moving iron design, not an mc. Extremely dynamic, immediate, and visceral sound!